Non-invasive ultrasonic body contouring

ABSTRACT

An apparatus for lysing adipose tissue, the apparatus comprising a power source and modulator assembly configured to supply modulated electrical power; an ultrasonic therapeutic transducer connected to said power source and modulator assembly and configured to convert the modulated electrical power to ultrasonic energy directed at a target volume in a region of a body containing adipose and non-adipose tissue, so as to selectively generally lyse the adipose tissue and generally not lyse the non-adipose tissue; an ultrasonic imaging sub-system configured to identify changes in the target volume resulting from the ultrasonic energy; and a lipolysis control computer configured to control said power source and modulator assembly based on the changes identified by said ultrasonic imaging sub-system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/071,382, filed Feb. 20, 2008, which is a continuation of U.S. patentapplication Ser. No. 10/021,238, now U.S. Pat. No. 7,347,855, filed Oct.29, 2001.

FIELD OF THE INVENTION

The present invention relates to lipolysis generally and moreparticularly to ultrasonic lipolysis.

BACKGROUND OF THE INVENTION

The following U.S. patents are believed to represent the current stateof the art: U.S. Pat. Nos. 4,986,275; 5,143,063; 5,143,073; 5,209,221;5,301,660; 5,431,621; 5,507,790; 5,526,815; 5,884,631; 6,039,048;6,071,239; 6,113,558; 6,206,873.

SUMMARY OF THE INVENTION

There is provided, in accordance with an embodiment, an apparatus forlysing adipose tissue, the apparatus comprising: a power source andmodulator assembly configured to supply modulated electrical power; anultrasonic therapeutic transducer connected to said power source andmodulator assembly and configured to convert the modulated electricalpower to ultrasonic energy directed at a target volume in a region of abody containing adipose and non-adipose tissue, so as to selectivelygenerally lyse the adipose tissue and generally not lyse the non-adiposetissue; an ultrasonic imaging sub-system configured to identify changesin the target volume resulting from the ultrasonic energy; and alipolysis control computer configured to control said power source andmodulator assembly based on the changes identified by said ultrasonicimaging sub-system.

In some embodiments, said ultrasonic imaging sub-system comprises anultrasonic imaging transducer and an ultrasonic reflection analyzer.

In some embodiments, the changes identified by said ultrasonic imagingsub-system comprise cavitation in the target volume.

In some embodiments, the changes identified by said ultrasonic imagingsub-system comprise lysis of adipose tissue in the target volume.

In some embodiments, said ultrasonic therapeutic transducer comprises adirector configured to vary a focus of the ultrasonic energy directedtowards the target volume.

In some embodiments, the varying of the focus comprises changing avolume of said target volume.

In some embodiments, the varying of the focus comprises changing adistance of said target volume from said ultrasonic therapeutictransducer.

There is further provided, in accordance with an embodiment, a methodfor selectively lysing adipose tissue, the method comprising: generatinga time-varying electrical signal having a series of relatively highamplitude portions separated in time by a series of relatively lowamplitude portions; converting the electrical signal to a correspondingultrasonic signal; and directing the ultrasonic signal towards a targetvolume in a region of a body containing adipose and non-adipose tissue,thereby inducing selective cavitation in the adipose tissue whilegenerally not lysing the non-adipose tissue in the target volume.

In some embodiments, the series of relatively high amplitude portionscomprises: one or more initial portions having amplitude above acavitation initiation threshold; and later portions having an amplitudeabove a cavitation maintenance threshold.

In some embodiments, the series of relatively low amplitude portionscomprises portions having amplitude below the cavitation initiation andmaintenance thresholds.

In some embodiments, the series of relatively high amplitude portionscomprises between 25-500 relatively high amplitude portions.

In some embodiments, the generating of the time-varying electricalsignal comprises generating the series of the relatively high amplitudeportions and the series of relatively low amplitude portions at a dutycycle of between 1:5 and 1:20.

In some embodiments, the ultrasonic signal has a frequency in the rangeof 150-1000 KHz.

There is yet further provided, in accordance with an embodiment, anautomatically-positionable adipose tissue lysis apparatus, comprising:an ultrasonic transducer secured to a three-dimensional positioningassembly, said ultrasonic transducer being configured to directultrasonic energy at a target volume in a region of a body containingadipose and non-adipose tissue, so as to selectively generally lyse theadipose tissue and generally not lyse the non-adipose tissue; alipolysis control computer having a video camera connected thereto, saidvideo camera being configured to externally image a portion of the body,and said lipolysis control computer being configured to detectindications on the imaged portion of the body; and a positioning controlunit configured to control said three-dimensional positioning assemblyso as to automatically position said ultrasonic transducer based on thedetected indications.

In some embodiments, the apparatus further comprises a lipolysis controlcomputer connected to said positioning control unit and configured tocontrol the directing of the ultrasonic energy from said ultrasonictransducer based on the detected indications.

In some embodiments, the apparatus further comprises an ultrasonicimaging sub-system connected to said lipolysis control computer andconfigured to identify changes in the target volume resulting from theultrasonic energy, wherein said lipolysis control computer is furtherconfigured to control the directing of the ultrasonic energy from saidultrasonic transducer based on the identified changes.

In some embodiments, the changes identified by said ultrasonic imagingsub-system comprise cavitation in the target volume.

In some embodiments, the changes identified by said ultrasonic imagingsub-system comprise lysis of adipose tissue in the target volume.

In some embodiments, the apparatus further comprises an ultrasonicimaging sub-system connected to said lipolysis control computer andconfigured to detect thicknesses of tissue layers in the region of thebody, wherein said lipolysis control computer is further configured tocontrol the directing of the ultrasonic energy from said ultrasonictransducer based on the detected thicknesses.

In some embodiments, said lipolysis control computer is furtherconfigured to control a focus of said ultrasonic transducer, so as tovary a distance of said target volume from said ultrasonic transducer.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description, taken in conjunction with thedrawings in which:

FIG. 1 is a simplified pictorial illustration of the general structureand operation of ultrasonic lipolysis apparatus constructed andoperative in accordance with a preferred embodiment of the presentinvention;

FIG. 2 is a simplified block diagram illustration of a preferred powersource and modulator showing a pattern of variation of ultrasonicpressure over time in accordance with a preferred embodiment of thepresent invention;

FIGS. 3A and 3B are simplified pictorial illustrations of the appearanceof an operator interface display during normal operation and faultyoperation respectively;

FIG. 4 is a simplified block diagram illustration of an ultrasoniclipolysis system constructed and operative in accordance with apreferred embodiment of the present invention; and

FIGS. 5A, 5B and 5C are together a simplified flowchart illustratingoperator steps in carrying out lipolysis in accordance with a preferredembodiment of the present invention.

DETAILED DESCRIPTION

Reference is now made to FIG. 1, which is a simplified pictorialillustration of the general structure and operation of ultrasoniclipolysis apparatus constructed and operative in accordance with apreferred embodiment of the present invention. As seen in FIG. 1, anultrasonic energy generator and director, such as an ultrasonictransducer 10, disposed outside a body, generates ultrasonic energywhich, by suitable placement of the transducer 10 relative to the body,is directed to a target volume 12 inside the body and is operative toselectively generally lyse adipose tissue and generally not lysenon-adipose tissue in the target volume.

A preferred embodiment of ultrasonic energy generator and directoruseful in the present invention comprises an ultrasonic therapeutictransducer 13 including a curved phased array 14 of piezoelectricelements 15, typically defining a portion of a sphere or of a cylinder,and having conductive coatings 16 on opposite surfaces thereof. Thepiezoelectric elements 15 may be of any suitable configuration, shapeand distribution. An intermediate element 18, formed of a material, suchas polyurethane, which has acoustic impedance similar to that of softmammalian tissue, generally fills the curvature defined by phased array14 and defines a contact surface 20 for engagement with the body,typically via a suitable coupling gel (not shown). Contact surface 20may be planar, but need not be.

Suitably modulated AC electrical power is supplied by conductors 22 toconductive coatings 16 to cause the piezoelectric elements 15 to providea desired focused acoustic energy output.

In accordance with a preferred embodiment of the present invention animaging ultrasonic transducer subassembly 23 is incorporated withintransducer 10 and typically comprises a piezoelectric element 24 havingconductive surfaces 26 associated with opposite surfaces thereof.Suitably modulated AC electrical power is supplied by conductors 32 toconductive surfaces 26 in order to cause the piezoelectric element 24 toprovide an acoustic energy output. Conductors 32, coupled to surfaces26, also provide an imaging output from imaging ultrasonic transducersubassembly 23.

It is appreciated that any suitable commercially available ultrasonictransducer may be employed or alternatively, imaging ultrasonictransducer subassembly 23 may be eliminated.

It is further appreciated that various types of ultrasonic transducers10 may be employed. For example, such transducers may include multiplepiezoelectric elements, multilayered piezoelectric elements andpiezoelectric elements of various shapes and sizes arranged in a phasearray.

In a preferred embodiment of the present invention shown in FIG. 1, theultrasonic energy generator and director are combined in transducer 10.Alternatively, the functions of generating ultrasonic energy andfocusing such energy may be provided by distinct devices.

In accordance with a preferred embodiment of the present invention, askin temperature sensor 34, such as an infrared sensor, may be mountedalongside imaging ultrasonic transducer subassembly 23. Further inaccordance with a preferred embodiment of the present invention atransducer temperature sensor 36, such as a thermocouple, may also bemounted alongside imaging ultrasonic transducer subassembly 23.

Ultrasonic transducer 10 preferably receives suitably modulatedelectrical power from a power source and modulator assembly 40, formingpart of a control subsystem 42. Control subsystem 42 also typicallyincludes a lipolysis control computer 44, having associated therewith acamera 46, such as a video camera, and a display 48. A preferredembodiment of power source and modulator assembly 40 is illustrated inFIG. 2 and described hereinbelow. Ultrasonic transducer 10 is preferablypositioned automatically or semi-automatically as by an X-Y-Zpositioning assembly 49. Alternatively, ultrasonic transducer 10 may bepositioned at desired positions by an operator.

In accordance with a preferred embodiment of the present invention,camera 46 is operative for imaging a portion of the body on whichlipolysis is to be performed. A picture of the portion of the patient'sbody viewed by the camera is preferably displayed in real time ondisplay 48.

An operator may designate the outline of a region containing adiposetissue. In accordance with one embodiment of the present invention,designation of this region is effected by an operator marking the skinof a patient with an outline 50, which outline is imaged by camera 46and displayed by display 48 and is also employed by the lipolysiscontrol computer 44 for controlling the application of ultrasonic energyto locations within the region. A computer calculated representation ofthe outline may also be displayed on display 48, as designated byreference numeral 52. Alternatively, the operator may make a virtualmarking on the skin, such as by using a digitizer (not shown), whichalso may provide computer calculated outline representation 52 ondisplay 48.

In addition to the outline representation 52, the functionality of thesystem of the present invention preferably also employs a plurality ofmarkers 54 which are typically located outside the region containingadipose tissue, but may be located inside the region designated byoutline 50. Markers 54 are visually sensible markers, which are clearlyseen by camera 46, captured by camera 46 and displayed on display 48.Markers 54 may be natural anatomic markers, such as distinct portions ofthe body or alternatively artificial markers such as colored stickers.These markers are preferably employed to assist the system in dealingwith deformation of the region nominally defined by outline 50 due tomovement and reorientation of the body. Preferably, the transducer 10also bears a visible marker 56 which is also captured by camera 46 anddisplayed on display 48.

Markers 54 and 56 are typically processed by computer 44 and may bedisplayed on display 48 as respective computed marker representations 58and 60 on display 48.

FIG. 1 illustrates the transducer 10 being positioned on the body over alocation within the region containing adipose tissue. Blocks designatedby reference numerals 62 and 64 show typical portions of a regioncontaining adipose tissue, respectively before and after lipolysis inaccordance with a preferred embodiment of the invention. It is seen froma comparison of blocks 62 and 64 that, in accordance with a preferredembodiment of the present invention, within the region containingadipose tissue, the adipose tissue, designated by reference numeral 66,is lysed, while non-adipose tissue, such as connective tissue,designated by reference numeral 68, is not lysed.

Reference is now FIG. 2, which is a simplified block diagramillustration of a preferred power source and modulator assembly 40 (FIG.1), showing a pattern of variation of ultrasonic pressure over time inaccordance with a preferred embodiment of the present invention. As seenin FIG. 2, the power source and modulator assembly 40 preferablycomprises a signal generator 100 which provides a time varying signalwhich is modulated so as to have a series of relatively high amplitudeportions 102 separated in time by a series of typically relatively lowamplitude portions 104. Each relatively high amplitude portion 102preferably corresponds to a cavitation period and preferably has adecreasing amplitude over time.

Preferably the relationship between the time durations of portions 102and portions 104 is such as to provide a duty cycle between 1:2 and1:250, more preferably between 1:5 and 1:30 and most preferably between1:10 and 1:20.

Preferably, the output of signal generator 100 has a frequency in arange of 50 KHz-1000 KHz, more preferably between 100 KHz-500 KHz andmost preferably between 150 KHz-300 KHz.

The output of signal generator 100 is preferably provided to a suitablepower amplifier 106, which outputs via impedance matching circuitry 108to an input of ultrasonic transducer 10

(FIG. 1), which converts the electrical signal received thereby to acorresponding ultrasonic energy output. As seen in FIG. 2, theultrasonic energy output comprises a time varying signal which ismodulated correspondingly to the output of signal generator 100 so as tohaving a series of relatively high amplitude portions 112, correspondingto portions 102, separated in time by a series of typically relativelylow amplitude portions 114, corresponding to portions 104.

Each relatively high amplitude portion 102 preferably corresponds to acavitation period and has an amplitude at a target volume 12 (FIG. 1) inthe body which exceeds a cavitation maintaining threshold 120 andpreferably has a decreasing amplitude over time. At least an initialpulse of each relatively high amplitude portion 112 has an amplitude atthe target volume 12, which also exceeds a cavitation initiationthreshold 122.

Relatively low amplitude portions 114 have an amplitude which lies belowboth thresholds 120 and 122.

Preferably the relationship between the time durations of portions 112and portions 114 is such as to provide a duty cycle between 1:2 and1:250, more preferably between 1:5 and 1:30 and most preferably between1:10 and 1:20.

Preferably, the ultrasonic energy output of ultrasonic transducer 10 hasa frequency in a range of 50 KHz-1000 KHz, more preferably between 100KHz-500 KHz and most preferably between 150 KHz-300 KHz.

Preferably, each high amplitude portion 112 is comprised of between 2and 1000 sequential cycles at an amplitude above the cavitationmaintaining threshold 120, more preferably between 25 and 500 sequentialcycles at an amplitude above the cavitation maintaining threshold 120and most preferably between 100 and 300 sequential cycles at anamplitude above the cavitation maintaining threshold 120.

Reference is now made to FIGS. 3A and 3B, which are simplified pictorialillustrations of the appearance of an operator interface display duringnormal operation and faulty operation respectively. As seen in FIG. 3A,during normal operation, display 48 typically shows a plurality oftarget volumes 12 (FIG. 1) within a calculated target region 200,typically delimited by outline representation 52 (FIG. 1). Additionally,display 48 preferably provides one or more pre-programmed performancemessages 202 and status messages 203.

It is seen the various target volumes 12 are shown with differentshading in order to indicate their treatment status. For example,unshaded target volumes, here designated by reference numerals 204 havealready experienced lipolysis. A blackened target volume 12, designatedby reference numeral 205 is the target volume next in line forlipolysis. A partially shaded target volume 206 typically represents atarget volume which has been insufficiently treated to achieve completelipolysis, typically due to an insufficient treatment duration.

Other types of target volumes, such as those not to be treated due toinsufficient presence of adipose tissue therein or for other reasons,may be designated by suitable colors or other designations, and are hereindicated by reference numerals 208 and 210.

Typical performance messages 202 may include “CAVITATION IN PROCESS” and“FAT LYSED IN THIS VOLUME”. Typical status messages 203 may include anindication of the power level, the operating frequency, the number oftarget volumes 12 within the calculated target region 200 and the numberof target volumes 12 which remain to undergo lipolysis.

Display 48 also preferably includes an graphical cross sectionalindication 212 derived from an ultrasonic image preferably provided byimaging ultrasonic transducer subassembly 23 (FIG. 1). Indication 212preferably indicates various tissues in the body in cross section andshows the target volumes 12 in relation thereto. In accordance with apreferred embodiment of the present invention, indication 212 may alsoprovide a visually sensible indication of cavitation within the targetvolume 12.

Turning to FIG. 3B, it is seen that during abnormal operation, display48 provides pre-programmed warning messages 214.

Typical warning messages may include “BAD ACOUSTIC CONTACT”,“TEMPERATURE TOO HIGH”. The “TEMPERATURE TOO HIGH” message typicallyrelates to the skin tissue, although it may alternatively oradditionally relate to other tissue inside or outside of the targetvolume or in transducer 10 (FIG. 1).

Reference is now made to FIG. 4, which illustrates an ultrasoniclipolysis system constructed and operative in accordance with apreferred embodiment of the present invention. As described hereinabovewith reference to FIG. 1 and as seen in FIG. 4, the ultrasonic lipolysissystem comprises a lipolysis control computer 44 which outputs to adisplay 48. Lipolysis control computer 44 preferably receives inputsfrom video camera 46 (FIG. 1) and from a temperature measurement unit300, which receives temperature threshold settings as well as inputsfrom skin temperature sensor 34 (FIG. 1) and transducer temperaturesensor 36 (FIG. 1). Temperature measurement unit 300 preferably comparesthe outputs of both sensors 34 and 36 with appropriate thresholdsettings and provides an indication to lipolysis control computer 44 ofexceedance of either threshold.

Lipolysis control computer 44 also preferably receives an input from anacoustic contact monitoring unit 302, which in turn preferably receivesan input from a transducer electrical properties measurement unit 304.Transducer electrical properties measurement unit 304 preferablymonitors the output of power source and modulator assembly 40 (FIG. 1)to ultrasonic therapeutic transducer 13.

An output of transducer electrical properties measurement unit 304 ispreferably also supplied to a power meter 306, which provides an outputto the lipolysis control computer 44 and a feedback output to powersource and modulator assembly 40.

Lipolysis control computer 44 also preferably receives inputs fromcavitation detection functionality 308, tissue layer identificationfunctionality 310 and lysed adipose tissue identification functionality312, all of which receive inputs from ultrasonic reflection analysisfunctionality 314. Ultrasonic reflection analysis functionality 314receives ultrasonic imaging inputs from an ultrasonic imaging subsystem316, which operates ultrasonic imaging transducer 23 (FIG. 1).

Lipolysis control computer 44 provides outputs to power source andmodulator assembly 40, for operating ultrasonic therapeutic transducer13, and to ultrasonic imaging subsystem 316, for operating ultrasonicimaging transducer 23. A positioning control unit 318 also receives anoutput from lipolysis control computer 44 for driving X-Y-Z positioningassembly 49 (FIG. 1) in order to correctly position transducer 10, whichincludes ultrasonic therapeutic transducer 13 and ultrasonic imagingtransducer 23.

Reference is now made to FIGS. 5A, 5B and 5C, which are together asimplified flowchart illustrating operator steps in carrying outlipolysis in accordance with a preferred embodiment of the presentinvention. As seen in FIG. 4A, initially an operator preferably draws anoutline 50 (FIG. 1) on a patient's body. Preferably, the operator alsoadheres stereotactic markers 54 (FIG. 1) to the patient's body andplaces transducer 10, bearing marker 56, at a desired location withinoutline 50.

Camera 46 (FIG. 1) captures outline 50 and markers 54 and 56.Preferably, outline 50 and markers 54 and 56 are displayed on display 48in real time. The output of camera 46 is also preferably supplied to amemory associated with lipolysis control computer 44 (FIG. 1).

A computerized tracking functionality preferably embodied in lipolysiscontrol computer 44 preferably employs the output of camera 46 forcomputing outline representation 52, which may be displayed for theoperator on display 48. The computerized tracking functionality alsopreferably computes coordinates of target volumes for lipolysistreatment, as well as adding up the total volume of tissue sought toundergo lipolysis.

Preferably, the operator confirms the locations of markers 54 and 56 ondisplay 48 and the computerized tracking functionality calculatescorresponding marker representations 58 and 60.

In accordance with a preferred embodiment of the present invention thecomputerized tracking functionality employs markers 54 and markerrepresentations 58 for continuously maintaining registration of outline50 with respect to outline representation 52, and thus of target volumes12 with respect to the patient's body, notwithstanding movements of thepatients body during treatment, such as due to breathing or any othermovements, such as the patient leaving and returning to the treatmentlocation.

The computerized tracking functionality selects an initial target volumeto be treated and positioning control unit 318 (FIG. 4), computes therequired repositioning of transducer 10. X-Y-Z positioning assembly 49repositions transducer 10 to overlie the selected target volume.

Referring additionally to FIG. 5B, it is seen that followingrepositioning of transducer 10, the lipolysis control computer 44confirms accurate positioning of transducer 10 with respect to theselected target volume. The ultrasonic imaging subsystem 316 (FIG. 4)operates ultrasonic imaging transducer 23, causing it to provide anultrasonic reflection analysis functionality 314 for analysis.

Based on an output from ultrasonic reflection analysis functionality314, the thicknesses of the various tissue layers of the patient aredetermined. Upon receiving an indication of the tissue layerthicknesses, an operator may approve the selected target volume andactivates the power source and modulator assembly 40 (FIG. 1).

Turning additionally to FIG. 5C, it is seen that the followingfunctionalities take place:

Transducer electrical properties measurement unit 304 provides an outputto acoustic contact monitoring unit 302, which determines whethersufficient acoustic contact with the patient is present, preferably byanalyzing the current and voltage at therapeutic transducer 13.

Transducer electrical properties measurement unit 304 provides an outputto power meter 306, which computes the average electrical power receivedby the therapeutic transducer 13. If the average electrical powerreceived by the therapeutic transducer 13 exceeds a predeterminedthreshold, operation of the power source and modulator assembly 40 maybe automatically terminated.

Skin temperature sensor 34 measures the current temperature of the skinat transducer 10 and supplies it to temperature measurement unit 300,which compares the skin temperature to the threshold temperature.Similarly, transducer temperature sensor 36 measures the currenttemperature at transducer 10 and supplies it to temperature measurementunit 300, which compares the transducer temperature to the thresholdtemperature. The outputs of temperature measurement unit 300 aresupplied to lipolysis control computer 44.

The ultrasonic imaging subsystem 316 operates ultrasonic imagingtransducer 23 and receives an imaging output, which is analyzed byultrasonic reflection analysis functionality 314. The result of thisanalysis is employed for cavitation detection and a cavitation detectionoutput is supplied to lipolysis control computer 44.

Should any of the following four conditions occur, the power source andmodulator assembly 40 automatically terminates operation of therapeutictransducer 13. Should none of the following conditions occur, theautomatic operation of power source and modulator assembly 40 continues:

1. Acoustic contact is insufficient.

2. Skin temperature exceeds threshold temperature level.

3. Transducer 13 temperature exceeds threshold temperature level.

4. Cavitation is not detected.

Returning to FIG. 5B, it is noted that during automatic operation ofpower source and modulator assembly 40, video camera 46 preferablyrecords the target region and notes whether the transducer 10 remainedstationary during the entire treatment duration of the selected targetvolume 12. If so, and if none of the aforesaid four conditions tookplace, lipolysis control computer 44 confirms that the selected targetvolume was treated. The computerized tracking functionality of lipolysiscontrol computer 44 then proposes a further target volume 12 to betreated.

If, however, the transducer 10 did not remain stationary for asufficient duration, the selected target volume is designated bylipolysis control computer 44 as having been insufficiently treated.

It is appreciated that by using multiple transducers multiplicity oftarget volumes can be treated at various time patterns such assequential time patterns or partially overlapping time patterns.

It is also appreciated that the multiplicity of target volumes may alsooverlap in space or partially overlap in space.

The computational tracking functionality is set forth in the ComputerProgram Listing Appendix of U.S. Pat. No. 7,347,855, which isincorporated herein by reference in its entirety.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove as well as variations and modifications whichwould occur to persons skilled in the art upon reading the specificationand which are not in the prior art.

1. An apparatus for lysing adipose tissue, the apparatus comprising: apower source and modulator assembly configured to supply modulatedelectrical power; an ultrasonic therapeutic transducer connected to saidpower source and modulator assembly and configured to convert themodulated electrical power to ultrasonic energy directed at a targetvolume in a region of a body containing adipose and non-adipose tissue,so as to selectively generally lyse the adipose tissue and generally notlyse the non-adipose tissue; an ultrasonic imaging sub-system configuredto identify changes in the target volume resulting from the ultrasonicenergy; and a lipolysis control computer configured to control saidpower source and modulator assembly based on the changes identified bysaid ultrasonic imaging sub-system.
 2. The apparatus according to claim1, wherein said ultrasonic imaging sub-system comprises an ultrasonicimaging transducer and an ultrasonic reflection analyzer.
 3. Theapparatus according to claim 2, wherein the changes identified by saidultrasonic imaging sub-system comprise cavitation in the target volume.4. The apparatus according to claim 2, wherein the changes identified bysaid ultrasonic imaging sub-system comprise lysis of adipose tissue inthe target volume.
 5. The apparatus according to claim 1, wherein saidultrasonic therapeutic transducer comprises a director configured tovary a focus of the ultrasonic energy directed towards the targetvolume.
 6. The apparatus according to claim 5, wherein the varying ofthe focus comprises changing a volume of said target volume.
 7. Theapparatus according to claim 5, wherein the varying of the focuscomprises changing a distance of said target volume from said ultrasonictherapeutic transducer.
 8. A method for selectively lysing adiposetissue, the method comprising: generating a time-varying electricalsignal having a series of relatively high amplitude portions separatedin time by a series of relatively low amplitude portions; converting theelectrical signal to a corresponding ultrasonic signal; and directingthe ultrasonic signal towards a target volume in a region of a bodycontaining adipose and non-adipose tissue, thereby inducing selectivecavitation in the adipose tissue while generally not lysing thenon-adipose tissue in the target volume.
 9. The method according toclaim 8, wherein the series of relatively high amplitude portionscomprises: one or more initial portions having amplitude above acavitation initiation threshold; and later portions having an amplitudeabove a cavitation maintenance threshold.
 10. The method according toclaim 9, wherein the series of relatively low amplitude portionscomprises portions having amplitude below the cavitation initiation andmaintenance thresholds.
 11. The method according to claim 9, wherein theseries of relatively high amplitude portions comprises between 25-500relatively high amplitude portions.
 12. The method according to claim 8,wherein the generating of the time-varying electrical signal comprisesgenerating the series of the relatively high amplitude portions and theseries of relatively low amplitude portions at a duty cycle of between1:5 and 1:20.
 13. The method according to claim 8, wherein theultrasonic signal has a frequency in the range of 150-1000 KHz.
 14. Anautomatically-positionable adipose tissue lysis apparatus, comprising:an ultrasonic transducer secured to a three-dimensional positioningassembly, said ultrasonic transducer being configured to directultrasonic energy at a target volume in a region of a body containingadipose and non-adipose tissue, so as to selectively generally lyse theadipose tissue and generally not lyse the non-adipose tissue; alipolysis control computer having a video camera connected thereto, saidvideo camera being configured to externally image a portion of the body,and said lipolysis control computer being configured to detectindications on the imaged portion of the body; and a positioning controlunit configured to control said three-dimensional positioning assemblyso as to automatically position said ultrasonic transducer based on thedetected indications.
 15. The apparatus according to claim 14, furthercomprising a lipolysis control computer connected to said positioningcontrol unit and configured to control the directing of the ultrasonicenergy from said ultrasonic transducer based on the detectedindications.
 16. The apparatus according to claim 15, further comprisingan ultrasonic imaging sub-system connected to said lipolysis controlcomputer and configured to identify changes in the target volumeresulting from the ultrasonic energy, wherein said lipolysis controlcomputer is further configured to control the directing of theultrasonic energy from said ultrasonic transducer based on theidentified changes.
 17. The apparatus according to claim 16, wherein thechanges identified by said ultrasonic imaging sub-system comprisecavitation in the target volume.
 18. The apparatus according to claim16, wherein the changes identified by said ultrasonic imaging sub-systemcomprise lysis of adipose tissue in the target volume.
 19. The apparatusaccording to claim 15, further comprising an ultrasonic imagingsub-system connected to said lipolysis control computer and configuredto detect thicknesses of tissue layers in the region of the body,wherein said lipolysis control computer is further configured to controlthe directing of the ultrasonic energy from said ultrasonic transducerbased on the detected thicknesses.
 20. The apparatus according to claim19, wherein said lipolysis control computer is further configured tocontrol a focus of said ultrasonic transducer, so as to vary a distanceof said target volume from said ultrasonic transducer.